Carpet cleaning systems that utilize heated water or steam to clean carpets are well known in the art. Typically, these systems direct a source of water through a pump driven by an engine. The pump then directs the water through a safety valve and from there to a heat exchanger. Heated water exits the heat exchanger, passes through a thermostat, and is then directed to a hand held carpet cleaning wand.
The wand houses a trigger mechanism that controls the flow of fluid through the wand and onto the carpet. The wand further includes a vacuum suction inlet port which collects residual waste water and directs the waste water back to a waste water recovery tank maintained under a vacuum by an engine driven blower or vacuum pump.
The heat exchanger may utilize the hot exhaust gases of the engine which drives the water pump and blower. Thus, the exhaust gases are generally directed onto coiled tubing or the like through which the water to be heated flows. However, such systems suffer from the inherent deficiency that the heat exchange process between the hot exhaust gases and the water to be heated is generally inefficient. That is, heat transfer between the engine's exhaust gases and the water to be used in the carpet cleaning process requires a larger heat exchanger than is generally desired. As such, it is desirable to provide an improved heat exchanger which maximizes the efficiency of the heat transfer process such that the size of the heat exchanger may be reduced while maintaining heating of the water to a desired temperature.
Furthermore, the exhaust from both the engine and the blower contribute a significant amount of undesirable sound. Thus, it would also be desirable to provide a means for quieting the carpet cleaning device by reducing the amount of sound produced by the engine and blower.